Having patients, doctors, health plan managers, hospital executives, and other stakeholders participate in the design of comparative effectiveness studies can ensure that this vital research focuses on the evidence gaps most relevant to health care decision makers. Through a qualitative assessment of case studies, we identify five key principles for the effective engagement of a broad coalition of participants in research intended to improve health care and control costs. Those principles are to ensure balance among the participating stakeholders; get participants to "buy in" to the process and understand their roles; provide neutral and expert facilitators for research discussions; establish connections among the participants; and keep the participants engaged throughout the research process.

There was a large increase in the number of mandated benefits laws during the managed care "backlash" of the 1990s. Many states now use mandated benefits to prescribe not only what services and benefits would be provided but how, where, and when services will be provided.

Significant variations currently exist for health insurance coverage of prophylactic mastectomy and oophorectomy. As genetic testing becomes widespread, more uniform policies should be established to enable appropriate high-risk candidates equal access and coverage for these procedures.

Methods: This article is based on the authors' experience reviewing benefit mandate bills for CHBRP and findings from evaluations of the program. General observations are illustrated with examples from CHBRP's reports. Information about efforts to incorporate evidence into health policymaking in other states and nations was obtained through a review of published literature.Findings: CHBRP produces reports that California legislators, legislative staff, and other major stakeholders value and use routinely in deliberations about benefit mandate bills. Where available, the program relies on previously published meta-analyses and systematic reviews to streamline the review of the medical literature. Faculty and staff responsible for the medical effectiveness sections of CHBRP's reports have learned four major lessons over the course of the program's six-year history: the need to (1) recognize the limitations of the medical literature, (2) anticipate the need to inform legislators about the complexity of evidence, (3) have realistic expectations regarding the impact of medical effectiveness reviews, and (4) understand the consequences of the reactive nature of mandated benefit reviews.